Recent Debris Events

Coverage started 2007 March 5

Updated 2007 March 5

2007 Feb 14: SL-12 Rocket Body Explosion

On February 16, I received a report from Jari Suomela in Finland regarding
some photographs taken by Jari Tuukkanen of an apparent debris cloud associated
with NORAD Catalog Number 25054, an SL-12 rocket body aux motor. The photographs
were taken from 62.878° N, 24.800° E, 152 m altitude, while the camera
was centered on 4h 8m right ascension, 27° 18' declination, at the times
shown below:

Analysis confirmed that NORAD Catalog Number 25054 was moving through the
field of view at the time of these photographs, but that no other objects in the
public satellite catalog (SATCAT) could be associated with these observations. These results were
reported to Cheyenne Mountain on February 21, but no new objects associated with
this event have been added to the public SATCAT as of this date. As
such, it is impossible at this time to determine when this event might have
occurred, although it was probably within a couple of hours of the
observations.

2007 Feb 19: BREEZE-M Rocket Body Explosion

As reported on Astronomy Picture of the
Day on February 22, Ray Palmer in Australia captured a BREEZE-M rocket body
explosion while taking a picture of the Milky Way on the morning of February 20.
His half-hour exposure photograph was taken from 01:50 to 02:17 WST (16:50 to
17:17 UTC on February 19) from Chittering Western Australia at 31° 27' S,
116° 06' E.

Photograph taken at 16:50 to 17:17 UTC

Analysis of this event confirms the passage of NORAD Catalog Number 28944
with excellent agreement, as seen in the figure below. No other objects in the
public catalog could be associated with this observation, but since the point
where the explosion first appeared (lower-right end of the streak) can be
correlated with the position of 28944 at 17:10:40 UTC, and that time is well
after the beginning of the exposure, it is reasonable to conclude that the event
occurred at that time. No objects associated with this event have yet been added
to the public SATCAT, however, so no additional confirmation is possible at this
time.

Initial analysis suggests these additional observations appear to agree well with those provided by Ray Palmer.

It appears that it is highly unlikely that this event is associated in any
way with the debris from the Chinese ASAT test, which was conducted in January.
While 28944 does pass through the debris ring (below the known debris) around
16:34 UTC—that is about 37 minutes before the event appears to begin. As can
be seen in the figure below, shown at the time the event appears to have occurred,
28944 is well outside the debris ring from the Chinese ASAT at this time.

View of NORAD Catalog Number 28944 and Chinese ASAT Debris Ring at Time of Apparent Explosion

An STK Viewer file of this event is provided to permit additional examination
of this event. In it, the orbit of 28944 is green, except during the time of Ray
Palmer's photographic exposure (16:50 to 17:17 UTC). During that time, the orbit
is yellow and the portion of the orbit which appears in his photograph (starting
at 17:10:40 UTC) is orange. There is a line from the observing location to 28944
throughout the time that 28944 was in the camera field of view (which is also
shown in yellow).

Note: STK Viewer is a free product which allows anyone
with a Windows computer to view an STK (System Tool Kit) scenario. With it,
you can animate a scenario forward or backward, pause the animation, and zoom or
pan the view for a more complete understanding of the event. Just like with
Adobe Acrobat, where the authoring software requires a license but the Adobe
Reader is free, STK can produce STK Viewer files—also known as
VDFs—which can then be viewed by anyone with the STK Viewer software. You
can find the free STK Viewer on CelesTrak
here. - TS